Selective interference with pacemaker activity by electrical dental devices.
OBJECTIVE
We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment.


METHODS
Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer.


RESULTS
Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm.


CONCLUSIONS
These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.
Miller
C S
CS
Oral Medicine, University of Kentucky College of Dentistry, Lexington 40536-0084, USA.
Leonelli
F M
FM
Latham
E
E
D001145:Arrhythmias, Cardiac / Q000209:etiology; D017742:Dental Care for Chronically Ill / Q000009:adverse effects*; D003748:Dental Equipment / Q000009:adverse effects*; D012534:Dental Scaling / Q000295:instrumentation; D004560:Electricity / Q000009:adverse effects; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004868:Equipment Failure; D006801:Humans; D010138:Pacemaker, Artificial; D014465:Ultrasonics / Q000009:adverse effects